Photographic printing material and process for using the same



March 2, 1943. P, cgoLln--INGh- R 2,312,543 N PHOTOGRAPHIC PRINTING MATERIAL AND PROCESS FOR USING THE vSAME Filed July 12, 1939 Patented Mar.` 2, 1943 PHOTOGRAPHIC PRINTING MATERIAL PROCESS FOR USING THE SAIVIE Paul Goldnger, Brussels-Uccle, Belgium, as-

signor, by mesne assignments, tovChromogen, Incorporated, a corporation of Ne Application July 12, 1939,l Serial No. 284,103 In Germany July 12, 1938- 11 Claims.

The present invention relates to a process for the production of color photographic images especially three color images by the use of a three layer taking material and a printing material containing three image layers which may, prior to exposure, contain the three dyes necessary for forming the image namely a blue-green, a, magenta and a yellow dye.

It is already known that for the production of a multi-color image, multi-layer materials containing pre-dyed layers can only be used in certain cases, i. e. if each one of the layersssontains a dye which is transparent for light of the component color which is to be recorded in the layer itself and also transparent for light of the component colors to be recorded in the subsequent layers. If, in the taking material, the blue comfponent color part-image is to be recorded in the i/ppermost layer then this layer must be transparent for blue light rays and also transparent for the green and the red light which is to be recorded in the subsequent layers. In prior specications, the applicant has already described taking materials, the front layer of which is colorless during the exposure and is dyed thereafter whereas the second layer contains a yellow dye serving as a light lter and subsequently for forming the image.

If images taken on this known material and thereafter converted into colored images are to be printed directly onto a pre-dyed multi-layer material without the use of intermediate prints of the diierent color component part-images, it has' hitherto been necessary to leave the front layer of this printing material also colorless and to dye it only after the exposure. By` means of the present invention this special treatment of A the front layer of the printing material can be avoided. y

For this purpose a new printing material is used and the treatment of the taking material is adjusted to the properties of the printing materials in a denite manner, i. e. in such a manner that the image formed in\the taking material can be printed onto the three layer printing material containing three layers of definite coloring. This process therefore allows the use of materials in which all the layers of the printing material are pre-dyed deiinitely during their preparation ranged as the rear layer and that the magenta and blue-green colored emulsion layers for the two other part-images are superimposed on the yellow emulsion layer. To render the exposure of such a material possible each o'i the three lay-1 ers is differently sensitized. The rear layer which is sensitive to the outermost part of the visible red light or for infra-red light is colored yellow. The adjacent layer is sensitized for blue light and the uppermost layer is sensitized for either red or green. In order that the blue light rays should inuence only the middle layer in which they are to be effective. and especially in order that they may not produce also the formation of a latent image in the overlying layer which is sensitive for red or green light, the uppermost emulsion layer is prepared from an emulsion which is many times less light-sensitive than the blue-sensitive emulsion lying below. To decrease the sensitivity of the front layer the same measures can be used which have already been described in connection with the manufacture of taking trl-packs, where lt-was intended Y to record the red and green part color partimages in the front layer and the blue part-image (which is of less importance for the appearance of the multi-color image) in the rear layer. These measures have not been employed with taking materials in practice because the decrease in the sensitivity to blue results in a decrease of the sensitivity to green or red light. Therefore, the front layer cannot be made with such a low sensitivity that, on the one hand, the blue light rays have practically no eect on this layer and yet, on the other hand, the green or red light rays are recorded to a suillcient extent ln spite of the necessarily short exposure times and limited light intensities available for the exposure. I'his consideration. is of no importance for a printing material because there is greater freedom in the choice of the printing light intensity rays in the blue-sensitive middle layer can be ascertained by calculation. The following convhigher the latitude of the object.

' material.

sideration of an example assumes the presence of the image dyes in thecolored layers but it is also applicable if these image dyes are introduced later. For the reproduction of a colored object by a subtractive three color image in a natural and aesthetically pleasing manner the dyes must be present in an increasing concentration, the For practical requirements, i. e. for the reproduction of a latitude of 2.5 an optical dye density of about 2.5 in logarithm units is suillcient, i. e. the subtractive effect of the dyes in all three of the colored layers oi the lm taken together practically corresponds to the effect of a silver deposit having the density 2.5. It. in such layers gray values are reproduced by colored part-images having a gradation 7:1,

or a gradation between the limits 0.8 and 1.2 the dye-images reproduce the latitude and the gradations of brightness of the object in a. true and aesthetically pleasing manner.. In order to print from a colored master image into the layers described, the colored image in the master image must graduate the printing light used for its printing in an image-like manner. Consequently, it is necessary for the production of a photographic copy showing suiilcient brightness delatitude of the object, i. e. at least 0.4 D. Ifthe printing light whose diierences at the brightest and darkest places are at least about 0.4 D in logarithm units is to iniluence only the bluesensitive layer .but not the green-'sensitive layer situated above, the green-sensitive layer must be at least numerus i. e., the antilog of 0.4 D times less sensitive for blue light than the green-sensitive layer is sensitive for the blue printing light. Thus in the case oi a dye density of about 2.5 the green-sensitive layer must be at least numerus 0.4 times 2.5, i. e. one logarithm unit or ten times less sensitive than the layer lying beneath. But to make more sure, an even greater decrease in the sensitivity is to be preferred because this decrease can berelatively easily equalized by increasing the intensity of the printing light. In

In th accompanying drawing I have shown diagrammatical cross sectional representations of different embodiments of my improved printing Fig. 1 illustrates one arrangement of colorings and sensitivities and Fig. 2 illustrates a modication of the material shown in Fig. 1.

Referring now to Fig. 1 a specicdescription oi' a typical printing material will be given; As

chrysophenine G (Schultz, l. c., No. 726) is present. The front layer i contains a blue-green Adye of the same kind, which is transparent for infra-red light, for example, the -naphthochinolinium salt of diamine sky blue FF (Schultz 1 c., No. 510). 1 the layers I, 2 and 3 are sensitive respectively to green, blue and red or infra-red light. As sensitizers, there can be used for red, pinacyanol; for green, benzothiopseudocyanine-ethyliodide and for infra-red kryptocyanine. As indicated by a legend layer I is a low speed silver bromide emulsion having,` for example, a sensitivity of 1,500 or even 1/000 of the sensitivity of layer' 2.

'Ihe preparation of colored print'swith the printing material described is carried out in the following manner: As the taking material, a three layer film is used, the front layer being vblue-sensitive and uncolored during the exposure, the middle layer being green-sensitive and'colored yellow by the diphenyl-guanidine salt of Chrysophenine Gand the rear layer being red-sensitive and colored magenta by Benzopurpurine 10 B (Schultz l. c., No. 489). After exposure and development of the silver images there is formed a yellow part-image from the dye contained in the yellow layer by image-like destruction, a magenta part-image from the rdye contained in the magenta layer, and in the originally colorless front layer there is formed by any of the known methods a corresponding dye-image in a color which is practically transparent for blue and green light rays and whichshows a good absorption power for infra-red light. Therefore, in this multi-color image the blue part-image is reproduced by an infra-red absorbing part-image, the

, green part-image by a yellow colored part-image already stated above the blue-sensitive layer 2 generally contains no further sensitizer but it contains only a dye for the formation of the imn: e, i. e. for example, a magenta dye such as the phenyl-guanidine salt of chlorantine red 8 B hultz Farbstotabellen, Leipzig 1931, vol.1,

"1th ed., N0. 425). This is a. dye which is stable Y z 1 tithe usual photographic treating baths, but which can be destroyed locally in dependence on the silver image by the use of the treating baths already described' by the applicant, for ex'- ample, solutions of thiocarbamide or halogen hydracl In the back layer 3, which is sensitized to infra-red light a yellow dye of the same kind,

for example, the diphenyl-guanidine salt of and the red part-image by a magenta colored This image is printed onto the new printing material described above with blue. `green and infra-red light by an optical or contact process. 'I'he printing light may vcomprise a mixture of these light rays or the different printing lights can be employed one after ,the other. t the printing light is graduatedin an image-like manner by the part-image of the master image which consists of infra-red absorbing dye and which corresponds to the blue part-image. In`

this image-like gradation the infra-red part of the light, penetrating through all the other layers, acts on the rear layer 3v of the printing material which is sensitive to infra-red and forms a latent image oi' the blue extract on the afore-A mentioned layer. The green portion of the printing light is graduated in an image-like fashion by the part-image of the master image consisting of magenta dye and corresponding to the red part-image and acts on the uppermost layer I of the printing material, which is sensitive for green light and colored blue-green, and in which it forms a latent image of the red part-image. 4

In view of the very low sensitivity of the greensensitive front layer I the time of exposure or the intensity of the green printing -light or its proportion in -the mixture of the different printing lights is increased to such an extent, that in spite of the layers lower sensitivity for example, to 1000 times less. a. suiilcient exposure'of the, iront layer to green light is obtained.

The blue portion of the printing light-does not act on the unsensitive front layer I but it is graduated in an image-like manner bythe yellow dye-image of the master image which corresponda to the green part-image and it acts, after As indicated by legends on Fig.

In doing this the infra-red portion of amata?.

penetrating the non-sensitive front layer.'on the blue-sensitive magenta emulsion layer 3 lying behind in which it forms a latent image of the green part-image. The latent images contained in the printing material are all' developed at the same time and the developedand, if necessary, nxed printing material is thereupon treated with a dye-destroying solution of the same kind used for the treatment of the taking material, i. e. a solution which bleaohes out in every part layer the dye contained therein in dependence on the silver image. In this manner there is obtained in the rear layer t the yellow dyed positive of the blue part-image, in the middle layer 2 the ma- .genta dyed positive of the green part-image, and

in the iront layer i the blue-green dyed positive oi the red part-image, i. e. the color-correct reproduction ofthe photographed object.

The example given above represents one manner of carrying out the invention; another manner of carrying out the same consists brieiiy in using a taking material in which the front layer is blue-sensitive and colorless, the second layer red-sensitive and dyed yellow and the third layer green-sensitive and dyed blue-green. The'ront layer is treated after the exposure with a substance which absorbs infra-red and which is practically transparent for the whole of the visibie spectrum and this substance is nxed at the nnexposed parts in an image-like manner. in this case a printing material such as shown in Fig. 2 is used the top layer b of which is redsensitive and dyed magenta, the next layer t blue-sensitive and dyed blue-green and the third layer i, as in the first example, 4inira-red-sensitive and dyed yellow. For printing, infra-red, red and blue light is used.

The same printing material can obviously also be used in other cases, for example, if the top colorless layer in the taking material is not to be converted into a dye-image but is used 'for the production ci a black silver image. This silver inage must be a positive if the dyes in the other layers are to be :formed as positive dye-images and vice versa. in the latter case there is used as the taking material a bil-paci: whose front layer is situated on a separate support. The two other layers on the rear support can be of the same sind as in the three layer taking material but the top one of these two layers can also be colorless ii a yellowfilter layer is arranged above the top layer, preferably behind the iront layer on the upper support only carrying one layer.

The dierent layers of the printing material may also contain additional filter dyes. which can be washed out or diiiusely destroyed and which are not used for forming the picture. These filter dyes can also be present in special intermediate layers and the presence of a blue or magenta lter dye behind the. frontrlayer and the presence of a yellow filter dye behind the 'middle' layer is advisable so that the light rays for which the foregoing light-sensitive layer is tographic prints which comprises, printing the color sensation records from a three-color original onto a multilayer light-sensitive printing material,. developing and'converting the print into a dye image, said three-color original comprising an infra-red-absorbing record representing the blue color sensation of the object,

a yellow record representing a second color sensation and a dye-record representing the third color sensation of the object, said dye-record being formed by a dye which is absorbent prev dominantly for light represented by said yellow record, said multilayer light-sensitive printing material comprising three dierently colored i is color sensitized for light represented by the yellow record in the said three-color original and the speed of the front emulsion being less than x16 of the speed of the blue-sensitive intermediate layer, the infra-red-sensitive layer comprising the yellow dye, the blue-sensitive intermediate layer comprising 'the dye which is selectively absorbent for light for which the front layer is predominantly color-sensitized, and the front layer comprising the third of said three dyes,

the step which comprises, printing the front layer of said printing material with light to which it is predominantly sensitized and having a timeintensity value sunicient to balance the exposure with respect to the blue sensitive intermediate layer of said printing material.

3. A light-sensitive multilayer printing material for the production of three-color pictures, comprising three differently sensitized silverhalide emulsion layers in superposition on a single support, the iront layer being a light-sensitive emulsion layer comprising silver bromide and being sensitized to light other than blue light, the middle layer being arranged behind said front layer beingv a blue-sensitive silver halide emulsion, said front layer having a speed which is less than 1% of the speed of the blue-sensi tive layer arranged behind it, said blue-sensitive layer comprising a dye which is highly absorbent or light for which the front layer is sen'- sitized and which is transmittant for light for which the third layer is sensitive and the third layer being predominantly sensitive to light other than blue light and other than light to which said front layer is sensitive and effectively insensitive to blue light transmitted by said middle layer.

4. A light sensitive multilayer printing material for the production of threev color pictures, comprising three diierently sensitized silver halide emulsion layers in superposition on a single support, the front layer being a light sensitive emulsion layer comprising silver bromide and being sensitized to light other than blue light, the middle layer arranged behind the said front layer being a blue-sensitive silver halide emulsion, said iront layer having a speed which is less than 116 of the speed of the blue-sensitive layer arranged behind it, and the third layer being predominantly sensitive to light other than blue light and other .than light to which. said front layer is sensitive and effectively insensitive to blue light transmitted by said middle layer;

5. A light sensitive multilayer printing material for the production of three color pictures, comprising three differently sensitized silver halide emulsion layers in super-position on a single support, one layer being dyed blue-green, another magenta, and the other yellow with image forming dyes, the front layer being a light sensitive emulsion layer comprising silver bromide and being sensitized tov light other than blue light, the middle layer arranged behind said front layer being a blue sensitive silver halide emulsion, said front layer having a speed which is less than 116 oi' the speed of the blue sensitive layer arranged behind it, the third layer being predominantly sensitive to light other than blue light and other than light to which said front layer is sensitive and containing said yellow image forming dye, said front layer being dyed with a second one of said image forming dyes which transmits light to which the layer is sensitive, and said middle layer being dyed with the third one of said image forming dyes.

6. A light sensitive multilayer printing material for the production of three color pictures,`

comprising three differently sensitized silver halide emulsion layers in super-position on a single support, the iront layer being a light sensitive emulsion layer comprising silver:v bromide and being sensitized to light other than blue light, the middle layer arranged behind said front layer being a blue sensitive silver halide emulsion, said front layer having a 4speed which is. at its maximum, to the speed of said blue sensitive emulsion layer arranged behind it as 1 is to the numerus of the product oi' 0.4 times the over all density difference in logarithmic units of the three color picture to be produced and the third layer being predominantly sensitive to light other than blue light and other than light to which said front layer is sensitive and effectively insensitive tn blue light transmitted by said middle layer.

7. A light sensitive multilayer printing material for the productionot three color pictures,

- predominantly sensitive to light other than blue comprising three diierently sensitized silver halide emulsion layers in super-position on a single support, one layer being dyed blue-green,

another magenta, and the other yellow with image forming dyes, the front layer being a light sensitive emulsion layer comprising silver bromide and being sensitized to light other than blue light, the middle layer arranged behind said front layer being a blue-sensitive silver halide emulsion, said front layer having a speed which is, at its maximum, to the speed oi said blue sensitive :emulsion layer arranged ibehind' it as 1 is to the/merus ofthe product of 0.4 times the over all density difference in logarithmic units of the three color picture to beV produced, the third layer being predominantly sensitive to light other than blue light and other than light to which said iront layer is sensitive and containing said yellow image forming dye, said front layer being dyed with a second one of said image vforming dyes which transmits light to which the layer -is sensitive, and said middle layer being dyed with the third one of said image forming dyes. i v

8. A light sensitive multilayer printing material for the production of three color pictures, comprising three diierently sensitized silver light and other than light to which said front layer is sensitive and effectively insensitive to blue light transmitted by said middle layer, mid a removable illter dye carried by a layer behind said front layer for absorbing light rays to which said front layer is sensitized.

a. A ught sensitive material comprising a siii ver halide emulsion rear layer which is sensitive to infra-red light and is colored yellow, a bluesensitive silver halide emulsion middle layer colored blue-green and a magenta colored silver halide emulsion iront layer'comprising silver bromide and being sensitized to red, the front layer having a speed less than 11e of that of the blue-sensitive middle layer.

10. A process for producing multicolor photographic pictures from a multi-color image in a multilayer material wherein the one layer contains a blue part image formed from an infra,- red absorbing dye, another`layer contains a yellow dye image of a second part image and the third layer contains a third part imageiormed from a dye which transmits blue light, light ot a spectral range represented by said third part image and infra-red light, which comprises printing said multi-colored image onto a light sensitive multilayer printing material, comprising three diii'erently sensitized silver halide emulsion layers in' superDOsition on 'a single support,

the front 'layer being a light` sensitive silver the multi-colored material, the middle layer of the printing material being a blue-sensitive silver halide emulsion, the third layer of the printing material being a silver halide emulsion layer sensitized to infra-red, and the front layer having a speed which is less than 11e of the speed of the blue-sensitive layer arranged behind it, the time-intensity value of the light used in printing animage into said cient to balance theY exposures necessary with respect to the blue-sensitive .middle layer; developing and producing superposed dye images which correspond tothe silver images in each of said layers. the dye image in the frontlayer of the printing material having a color complementary to the spectral range `represented by said third part image, the dve image in the rear layer of the printing material being yellow and, the dye image in the middle layer of the printing material having a color complementary to the spectral range 'represented by said second part image. 11. A process for producing multicolor ph image andra multi-color multilayer illm com. prising one layer which contains a yellow' dye iront layer of said printing material being suiilimage of a secondpart image and another layer v which contains a third part image formed from a dye which transmits blue light and light of a spectral v range represented by said third part halide emulsion layers in super-position on a '15y image. which Comprises printing in separate steps said black and white silver image with infra-red light and said multi-color image onto a light sensitive multilayer printing material, comprising three differently sensitized silver halide emulsion layers in superposition on a single support, the front layer being a light sensitive silver halide emulsion which is inherently blue sensitive and which -is sensitized to light represented by the yellow colored part image in the multi-color material, the middle layer of the printing material being a blue-sensitive silver halide emulsion, the third layer of the print-n ing material being a silver halide emulsion layer sensitized to infra-red, and the front layer having a. speed which is less than 11a of the speed of the blue-sensitive layer arranged behind it,

the time-intensity value of the light used in printing an image into said front layer of said printing material being suiiicient to balance the exposure necessary with respect to the bluesensitive middle layer; developing and producing superposed dye images which correspond to. the silver images in each of said layers, the Adye image in the front layer of the printing material having a color complementary to the spectral range represented by said third part image, the. dye image in the rear layer of the printing material being yellow and, the dye image in the middle layer of the printing material having la color complementary to the spectral range represented by said second part image.

PAULIGOIDFINGER. 

